Show error message from failed evaluation when doing -var-create

[ki.stfu]

Summary

When -var-create fails, we will now show the error message from the failed evaluation if it is available.

Patch from [e-mail]

[ki.stfu]

Rebase against ToT

[ki.stfu]

Minor fixes

[ChuckR]

Thank you.

test/tools/lldb-mi/variable/TestMiVar.py

 
         # Print non-existant variable
         self.runCmd("-var-create var1 * undef")
-        self.expect("\^error,msg=\"Failed to create variable object for 'undef'\"")
+        self.expect("\^error,msg=\"error: error: use of undeclared identifier \'undef\'\s+error: 1 errors parsing expression\"")
         self.runCmd("-data-evaluate-expression undef")
         self.expect("\^error,msg=\"Could not evaluate expression\"")
 

tools/lldb-mi/MICmdCmdVar.cpp

         CMICmnLLDBDebugSessionInfoVarObj varObj(rStrExpression, m_strVarName, value);
         m_strValue = varObj.GetValueFormatted();
     }
+    else 
+    {
+        lldb::SBStream err;
+        value.GetError().GetDescription(err);
+        m_strValue = err.GetData();
+    }
 
     return MIstatus::success;
 }

         return MIstatus::success;
     }
 
-    const CMICmnMIValueConst miValueConst(CMIUtilString::Format(MIRSRC(IDS_CMD_ERR_VARIABLE_CREATION_FAILED), m_strExpression.c_str()));
+    CMIUtilString errmsg;
+    if (!m_strValue.empty())
+    {
+        errmsg = m_strValue;
+    }
+    else
+    {
+        errmsg = CMIUtilString::Format(MIRSRC(IDS_CMD_ERR_VARIABLE_CREATION_FAILED), m_strExpression.c_str());
+    }
+    const CMICmnMIValueConst miValueConst(errmsg);
     CMICmnMIValueResult miValueResult("msg", miValueConst);
     const CMICmnMIResultRecord miRecordResult(m_cmdData.strMiCmdToken, CMICmnMIResultRecord::eResultClass_Error, miValueResult);
     m_miResultRecord = miRecordResult;